Molecular characterization of human factor XSan Antonio

Enzymatic amplification technique was used to isolate all eight exons and sequences around the splice junctions, putative promoter, and polyadenylation sites of human factor X DNA from a patient with factor X deficiency. Two genetic changes in factor X have been observed in this patient. The patient is most likely a compound heterozygote since there is only 14% activity associated with factor X. A point mutation that resulted in the substitution of cysteine (TGC) for arginine (CGC) at amino acid 366 was found in exon VIII of one allele of the factor X gene. This mutation, which occurs in the catalytic domain, can affect the formation of a disulfide bridge and thus could result in a reduction in factor X activity. Sequencing all the regions revealed a second mutation: a deletion of one nucleotide (TCCT to TCT) in exon VII that would cause a frame shift at amino acid 272 followed by termination. We have also shown that the point mutation in exon VIII creates an ApaL1 restriction site and destroys the HinP1 site. Enzymatic DNA amplification followed by restriction digestion provides a quick, reliable, and sensitive method for carrier detection and antenatal diagnosis in affected kindreds. This is the first characterization of factor X deficiency at the molecular level. We propose to name this mutation Factor XSan Antonio.     

腘绳肌腱重建前交叉韧带移植肌腱的固定

目的:腘绳肌腱重建前交叉韧带曾出现过多种固定器材,分析近年来关于腘绳肌腱重建前交叉韧带的文献资料,了解肌腱固定方式的发展趋势。资料来源:通过计算机检索Medline1995-01/2006-09有关腘绳肌腱重建前交叉韧带移植肌腱固定方式的文献,检索词为“anteriorcruciate ligament,reconstruction,hamstring”,限定文章语言种类为English;另外检索中文期刊全文数据库2000-01/2006-03有关腘绳肌腱重建前交叉韧带移植肌腱固定方式的文献,检索词为“前交叉韧带,重建术,腘绳肌腱”,限定文章语言种类为中文。资料选择:选取有关腘绳肌腱重建前交叉韧带的文章,纳入标准:①随机或自身前后对照的临床研究。②观点明确。③有关于固定方式的评论。排除标准:①综述。②重复性研究。资料提炼:共检索到60篇关于腘绳肌腱重建前交叉韧带的文章,选择其中符合标准的33篇进行综合分析。资料综合:固定方式经历了一个由皮质骨外固定到骨隧道内固定的演变过程,Transfix是目前较为理想的固定方式,肌腱结嵌压固定是最新出现的一种固定方式,其临床效果尚需进一步验证。在固定位置的选择上,多数学者认为应该遵循等距重建。通过对固定方式的比较发现,隧道内固定能减轻术后骨隧道的扩大程度。结论:腘绳肌腱重建前交叉韧带的固定方法越来越趋于隧道内固定,并朝着利于腱骨愈合、减轻骨隧道扩大的方向发展。在固定位置的选择上,学者们尚无统一的意见,其趋势可能是向解剖固定发展。     

猪胸腰段脊髓火器贯通伤后p53基因的早期表达

目的:建立家猪胸腰段脊髓火器贯通伤模型和改良Allen's打击伤后全瘫模型,观察伤后促凋亡基因p53基因的早期表达。方法:实验于2005-05/08在解放军第一七五医院实验室完成。取健康雄性家猪20只,单纯随机分为3组:①火器伤组:9只,在全麻状态下制作胸腰段(L1～L2)脊髓火器伤模型,分为伤后1,3,6h3个时间处死。②打击伤组:9只,L1节段脊髓行改良Allen’s打击,致伤力为500g·cm,处死时间同前。③空白对照组:2只,只麻醉,不造模,伤后6h处死。伤后不同时间点(伤后1,3,6h)和不同节段(伤点、近伤点、中伤点及远伤点)取材,采用SP法进行P53蛋白免疫组化染色,用TJTY-300型全自动图像分析仪测量P53免疫组织化学染色阳性物质吸光度。结果:经补充后20只猪进入结果分析。①脊髓损伤后3h打击伤组伤点,火器伤组近伤段脊髓P53蛋白的表达高于空白对照组(P<0.001),随着时间推移,打击伤组和火器伤组P53蛋白的表达呈升高趋势(P<0.001),且火器伤组要高于打击伤组(P<0.0001)。②在脊髓损伤后6h,打击伤组仅在伤点和近伤段P53蛋白的表达高于空白对照组(5.57±0.82,3.21±0.43,P<0.05),而火器伤组近伤段、中伤段及远段伤均高于空白对照组(6.46±0.66,4.27±0.39,1.16±0.17,P<0.05)。结论:①细胞凋亡基因p53在脊髓损伤中的表达有一定的时空性,在脊髓损伤后3h出现P53蛋白表达量的增加。②脊髓火器伤的波及范围较打击伤更为广泛。     

Interleukin-3 treatment of rhesus monkeys leads to increased production of histamine-releasing cells that express interleukin-3 receptors at high levels

To understand the hematopoietic and nonhematopoietic responses to interleukin-3 (IL-3), expression of cell-surface IL-3 receptors (IL-3R) was examined on bone marrow (BM) cells and peripheral blood (PB) cells of rhesus monkeys during the course of in vivo IL-3 treatment. Whereas IL-3R expression is low in untreated monkeys, IL-3 administration led to a gradual increase in both low- and high-affinity binding sites for IL-3. This increase reflected the total number of cells expressing IL- 3Rs, as detected by flow cytometry using biotinylated IL-3. Most of these IL-3R+ cells in both BM and PB could be characterized as basophilic granulocytes that contained high levels of histamine. In contrast to the effect on these differentiated cells, IL-3 administration did not significantly alter the low level IL-3R expression on immature, CD34+ cells. Further flow cytometric analysis using biotinylated growth factors showed that the IL-3R+ basophils also expressed receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF), but not for IL-6 or Kit ligand. These findings indicated that the IL-3R+ cells included neither monocytes, which express GM-CSFRs and IL-6Rs abundantly, nor mast cells, which express c- kit. By combining flow cytometric and Scatchard data, it was calculated that the basophils contain as many as 1 to 2 x 10(3) high-affinity IL- 3Rs and 15 to 30 x 10(3) low-affinity sites. The finding that in vivo IL-3 treatment leads to the production of large numbers of cells that express high levels of IL-3R and are capable of producing histamine provides an explanation for the often severe allergic reactions that occur during prolonged IL-3 administration. It also indicates that IL- 3, in addition to its direct effects on hematopoietic cells, may also stimulate hematopoiesis through the release of secondary mediators such as histamine by IL-3-responsive mature cells.     

Patterns and Correlates of Sexual Activity and Condom Use Behavior in Persons 50-Plus Years of Age Living with HIV/AIDS

This study characterized rates of sexual activity and identified psychosocial and behavioral correlates of sexual activity and condom use in a metropolitan sample of 290 HIV-infected adults 50-plus years of age. Thirty-eight percent of participants were sexually active in the past three months, 33% of whom had at least one occasion of anal or vaginal intercourse that was not condom protected. Rates and correlates of sexual activity and condom use differed between gay/bisexual men, heterosexual men, and heterosexual women. In the past three months, 72% of heterosexual men were sexually active compared to only 36% of gay/bisexual men and 21% of heterosexual women. However, among sexually active persons, only 27% of heterosexual men reported inconsistent condom use compared to 37% of gay/bisexual men and 35% of heterosexual women. As the number of older adults living with HIV/AIDS in the U.S. continues to increase, age-appropriate secondary risk-reduction interventions are urgently needed.     

Silent myocardial ischemia: Current perspectives and future directions

Silent myocardial ischemia (SMI) is increasingly being recognized as part of the spectrum of ischemic heart disease. The spectrum of SMI ranges from asymptomatic coronary artery disease to critical illness necessitating intensive care. Although many diagnostic tools have been used to identify low- and high-risk subgroups, their use is limited by modest sensitivities and specificities. The present review identifies current concepts in the management of SMI in various clinical settings, as well as emerging technologies that may simplify the diagnosis and treatment of this condition.     

Ca2+ and phospholipid-dependent protein kinase (protein kinase C) activity is not necessarily required for secretion by human neutrophils

Ca2+-dependent and phospholipid-dependent protein kinase (PKC) is a receptor for and is activated by phorbol esters. This enzyme is reportedly involved in the mechanism of superoxide anion (O2-) production and the release of intracellular granule contents from human neutrophils. As previously reported by others, we found that greater than 75% of the total cellular PKC activity existed in a soluble form in untreated neutrophils and that this activity was enhanced in a dose- dependent manner by phorbol 12-myristate 13-acetate (PMA) and by phorbol 12,13-dibutyrate (PDBu). Furthermore, mezerein, an analogue of PMA that is thought to be a competitive inhibitor, did not activate PKC, and on the contrary, inhibited PMA-stimulated activity in a dose- dependent manner. Pretreatment of intact neutrophils with PMA or PDBu caused the "translocation" of PKC activity to the insoluble cell fraction; PKC translocation was not detected after mezerein stimulation at any of the tested concentrations. Neither did mezerein cause an increase in intracellular Ca2+, as monitored by Quin 2 fluorescence. Both phorbol esters and mezerein stimulated intact neutrophils to generate O2- and release lysosomal enzymes into the extracellular medium. Finally sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis demonstrated key differences in the patterns of endogenous phosphoproteins of neutrophils stimulated with phorbol as compared with mezerein. We therefore suggest that PKC activation may not be the only pathway required to elicit neutrophil responses.